Never played the 3rd edition but I'd say it's the same as in the 4th.
Here it is described quite in detail:

This spell enhances the use of the Astral Sight talent. The magician rolls his eyes upward and makes a Spellcasting test against his Mystic Defense. If successful, he is able to use the Astral Sight talent without taking Strain, and is able to sense magical presences that are not otherwise in his line of sight (for example, behind him, or otherwise hidden). The enhancements to Astral Sight only apply to targets within the area of effect. A magician will often take a few moments after casting the spell to sweep the area and verify that an astral presence is not coming from a comrade. A magician may attempt to cast spells on a target that he has astrally sensed, even if he cannot otherwise see the target.
Magicians use this spell for many different reasons. It is often cast to make extended astral examinations less taxing. As with normal uses of Astral Sight, a magician using Astral Sense to view a thread item can sense the item’s true pattern and would learn it was magical in nature. However, he would not gain any information about the item’s history or learn any Key Knowledge.

So he would be able to distinguish a namegiver from a creature or magic object but without an additional test on e.g. Patterncraft I wouldn't give him the information what exactly it is he is sensing (e.g. a magic sword or staff).
As for namegivers: If the astral sense test is high enough, I would give him a few additional information like "Is it an adept?", "Perhaps even the discipline (if known / already sensed astral before somewhere) and ~circle", "or even the race".